title: Revised equations for estimating glomerular filtration rate based on the Lund-Malmö Study cohort.
abstract: OBJECTIVE
  To increase the accuracy of estimated GFR (eGFR) from creatinine overall and at measured GFR ≥90 mL/min per 1.73 m(2) by revising the Lund-Malmö (LM) equations, to elaborate on more complex forms to improve the LM and CKD-EPI equations further, and to assess benefits of adding lean body mass (LBM).
  
  
  METHODS
  Swedish Caucasians (n = 850, 376 women; median 60, range 18-95 years) referred for GFR measurement (plasma iohexol-clearance: median 55, range 5-173 mL/min/1.73 m(2)) constituted the Lund-Malmö Study cohort. Bias, precision, accuracy, expressed as median absolute percentage difference and percentage of estimates ±10% (P(10)) and ±30% (P(30)) of measured GFR, and classification ability with respect to five GFR stages were compared with the original LM, CKD-EPI and MDRD equations.
  
  
  RESULTS
  LM Revised overall performed better than LM Original without LBM due to increased accuracy at measured GFR ≥90 mL/min/1.73 m(2). Further extensions of the CKD-EPI or LM equations did not substantially improve overall performance. In particular, the performance of LM Revised at measured GFR ≥90 mL/min/1.73 m(2) could not be improved further without decreasing accuracy and classification ability at lower GFR-levels. Adding LBM to the equations had no strong effect on accuracy.
  
  
  CONCLUSIONS
  Comparisons with the CKD-EPI and MDRD equations suggest that the LM equations are superior for the present Swedish population, due to markedly higher accuracy of the LM equations at measured GFR <30 mL/min/1.73 m(2). However, the LM equations cannot be recommended for use in general clinical practice until validated in other populations.
authors.affiliation: Competence Centre for Clinical Research, Skåne University Hospital, Lund, Sweden. jonas.bjork@skane.se
authors.forename: Jonas
authors.initials: J
authors.lastname: Björk
authors.forename: Anders
authors.initials: A
authors.lastname: Grubb
authors.forename: Gunnar
authors.initials: G
authors.lastname: Sterner
authors.forename: Ulf
authors.initials: U
authors.lastname: Nyman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D015331:Cohort Studies; D003404:Creatinine / Q000097:blood; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007676:Kidney Failure, Chronic / Q000503:physiopathology; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D003404:Creatinine